What causes frothing in Delhi’s Yamuna?

• Recently, a layer of froth was seen floating over parts of the Yamuna river, which has now become a repeat occurrence in Delhi.
• Earlier, high levels of ammonia in Yamuna resulted in frequent disruption to Delhi’s water supply.

Why is River Yamuna Frothing?

• Froth means a mass of small bubbles on a liquid surface. It is also referred to aggregation of bubbles on an agitated liquid.
• Since Yamuna River water falls from a great height in Okhla barrage, it leads to bubble formation. Also, during winters the temperature dips to near zero.
• Hence, foam formation is accompanied. The chemical factors responsible for foam formation and frothing is Ammonia increase from untreated household waste containing detergent and phosphorous increase in effluent released from industries etc.
• The froth on Yamuna river reflects the adverse impact of manmade activities on environment and urgent steps are to be made on this regard to prevent further deterioration.

How and where do the effluents enter River Yamuna?

• Most of the pollution of river Yamuna comes from Wazirabad where it enters Delhi.
• According to the Delhi Pollution Control Committee and the CPCB (Central Pollution Control Board), 90% of the domestic wastewater in the city flows into river Yamuna. Around 58% of the waste of the national capital is dumped into the river.
• The waste water mainly comes from household activities and therefore it is highly rich in phosphate compounds, laundry chemicals and detergents.
• The samples collected show that the phosphate concentration in the river is 0.51 mg/litre. It should be between 0.005 and 0.05 mg/litre.
• More than 800 million litres of untreated sewage is dumped into Yamuna every day. Also, around 44 million litres of industrial effluents are discharged in to the river. CPCB says that the river water contains 1.1 billion faecal coliform bacteria per 100 millilitres of water.
• The permissible level is 500 coliform bacteria per 100 millilitres.

Yamuna

• Source:The river Yamuna, a major tributary of river Ganges, originates from the Yamunotri glacier near Bandarpoonch peaks in the Mussoorie range of the lower Himalayas at an elevation of about 6387 meters above mean sea level in Uttarkashi district of Uttarakhand.
• Basin: It meets the Ganges at the Sangam (where Kumbh mela is held) in Prayagraj, Uttar Pradesh after flowing through Uttarakhand, Himachal Pradesh, Haryana and Delhi.
• Length: 1376 km
• Important Dam: Lakhwar-Vyasi Dam (Uttarakhand), Tajewala Barrage Dam (Haryana) etc.
• Important Tributaries: Chambal, Sindh, Betwa and Ken.

Steps Taken to Stop Froth Formation:

• The Delhi Pollution Control Committee (DPCC) banned the sale, storage and transportation of soaps and detergents not conforming to the quality standards set by the Bureau of Indian Standards (BIS).
• The fifth report of the National Green Tribunal (NGT)-appointed Yamuna Monitoring Committee notes that though BIS standards for detergents have been improved, it is not clear whether these standards will actually be enforced.
• The role of regulatory bodies like the Central Pollution Control Board (CPCB), DPCC and Pollution Control Boards (PCBs) is generally limited to implementing discharge/effluent standards.